Sidekiq uses threads to handle many jobs at the same time in the same process. It does not require Rails but will integrate tightly with Rails 3/4 to make background processing dead simple.

Sidekiq is compatible with Resque. It uses the exact same message format as Resque so it can integrate into an existing Resque processing farm. You can have Sidekiq and Resque run side-by-side at the same time and use the Resque client to enqueue jobs in Redis to be processed by Sidekiq.

At the same time, Sidekiq uses multithreading so it is much more memory efficient than Resque (which forks a new process for every job). You’ll find that you might need 10 200MB resque processes to peg your CPU whereas one 300MB Sidekiq process will peg the same CPU and perform the same amount of work.

Ruby and Rails (RoR) is a great programming language and framework for developing a (not to heavy) scalable web application together with your teams. The convention is very clear and everyone naturally will be forcedto follow it rules for their own sake.